The women were attacked within four days, the first on January 8, and the incidents have prompted warnings to be vigilant and alert.

Chief Inspector Jim Pegler told The News: ‘What concerns me about this series of robberies, which we’re linking via modus operandi, and mainly location, is the level of violence which is being used towards females victims on two occasions when they’ve resisted the robbery.

‘We’ve seen what I would call a sustained attack with punches and kicks to head and body to females as old as 81.

‘That’s quite unusual and indicates a level of desperation.’

Extra patrols by uniformed and plainclothes officers are being carried out across the area over the weekend.

Ch Insp Pegler added: ‘This really is important for us and we hope to lock someone up soon.

‘I would say this is the policing priority for Hampshire Constabulary at the moment in terms of engaging operational resources – we’re bringing in resources from the area.

‘The trauma involved in a sustained attack like that probably impacted if not more than the physical injuries.

‘We have the greatest of sympathies for them.’

Investigators probing the four incidents are working out of Fratton police station, in Kingston Crescent, analysing seized CCTV and hunting for witnesses to the robberies.

CCTV was released as police step-up the investigation.

The four robberies were:

n January 8: A 39-year-old woman approached from behind in Campbell Road, Southsea. Her handbag was pulled, dragging her to the ground and snapping the strap at 2.30pm.

n January 10: At 3.45pm a 79-year-old woman was robbed in Victoria Road North when a man grabbed her handbag and attacked her at 3.45pm.

n January 11: The suspect punched a 63-year-old women in the face, knocking her to the ground and leaving her with swelling and bruising in Boulton Road, Southsea, at 11.15am. She kept hold of her bag and the man fled.

n January 12: An 81-year-old woman was pushed over and had her shopping bag and purse stolen in Outram Road, Southsea, at 11.15am.

The suspect is described as 5ft 5ins to 5ft 7ins tall, skinny or slim, possibly had a goatee-style beard and was wearing a dark-coloured jacket and hat or hood.